Perfluorocarbon Tracers (PFTs) are small perfluoroalkyl molecules that have been used as tracers to track or definitively mark a variety of objects, such as currency, drugs, crops, chemical compounds, vehicles, goods in commerce, letters, parcels, briefcases, paper documents, or people. PFTs are safe, volatile, non-reactive, environmentally benign compounds that are virtually non-existent (less than parts per quadrillion) in nature. Therefore, PFTs are detectable in the environment at extremely low levels, on the order of parts per trillion or less. The ambient background concentrations of the five routinely used PFTs are in the range of parts per 10E+15 of air. As such, PFTs may be easily and accurately detected and are finding use as specific tracker/taggant molecules in a variety of law enforcement and homeland security operations or missions. In order to function effectively as a taggant, the PFT must be of sufficient concentration in air as to enable unambiguous identification or detection, and also must be sufficiently long-lasting as to fulfill various mission parameters. The PFT is typically incorporated into a matrix, such as wax, a polymer, such as a urea-formaldehyde polymer, a liposome, a polysaccharide, a plastic, such as a polyvinylidene fluoride, or a large molecule inclusion complex, such as cyclodextrin. One barrier to improving the use and effectiveness of this PFT technology is the ability to release the PFT in a time-dependent manner. Since the release profile of the PFT from the matrix is typically a function of the PFT, the release profile of the PFT is static and cannot be adjusted or tuned to meet the requirements of different operations. As a consequence, there is insufficient control of the release profile for many potential operations, such as release of the PFT over a long duration of time. Therefore, the effectiveness and widespread adoption of this technology to date has been severely limited.
It would be desirable to be able to control or adjust the release of the PFT to provide flexibility for different operations. The ability to provide an optimized release profile for a wide variety of missions will enable the PFTs to be utilized in a broad array of operations, both for domestic security as well as information gathering abroad. To accomplish this, a versatile material is needed that may be easily and reliably tailored, enabling the release rate of the PFT to be tailorable over a range of conditions.